Over on Habitica in the geology guild, people were posting about the most interesting geological site they had visited. Here in Wales we are very lucky that we have just about the whole geological succession available in a very small country, which makes it an excellent place to study geology. But the most interesting geological location I've visited recently was interesting more for the role it played in the foundation of the science of geology rather than anything terribly exciting about the rock itself.

There's a pretty uninteresting looking hill called Foel Tryfan near Caernarfon and at the top is a rock that clearly consists of beach pebbles stuck together.

In Victorian times this outcrop was the subject of intense arguments between those who said it was proof of Noah's flood and those who preferred a glacial theory of origin, suggesting that the glaciers had scooped up pebbles from the nearby beach and deposited them on the top of the hill.

Of course both were completely wrong because the rock is in fact very early Cambrian, but Charles Darwin visited the site and it was quite amazing to stand there looking at the outcrop and thinking how the actual famous Charles Darwin had stood in the exact same spot at the time when geology was just developing as a separate science.

And here's the big quarry that was just over the top of the hill. There would have been glorious views over towards Penrhyn Llŷn in one direction and Anglesey in the other, but as you can see, the weather was very grey and so we need to go back another time to take better photos.

I find quarries very hard to photograph because they are so big. That one actually came out better than most.

All the photos so far have been taken with the Canon PowerShot or even the phone and are sort of placeholders for the illustrations required for G's geology book. Once he knows exactly which photos he wants, we'll go back and I'll take the DSLR and a tripod and choose a day with good light and see if I can do better.